1. Technical Field
The present invention relates to a recording apparatus that includes a recording head having a nozzle row that discharges a photoreactive liquid onto a recording target material, and a light irradiation unit having a light emitting row made up of light emitting elements aligned in the same direction as the nozzle row. The light emitting elements apply light to the discharged photoreactive liquid to cause the photoreactive liquid to undergo a chemical change.
2. Related Art
A recording apparatus including a recording head having nozzle rows in which a large number of nozzle openings for discharging optically-curable ink (e.g., ultraviolet (UV) curable ink) onto a recording target surface of a recording target material (hereinafter also referred to as “paper”) are arranged, and a light irradiation unit having a light emitting element row in which a plurality of light emitting elements (e.g., Light Emitting Diodes: LEDs) for applying light to the discharged optically-curable ink to cure the optically-curable ink are arranged has been developed as disclosed in JP-A-2005-104108 and JP-A-2004-314304.
In the case of a recording apparatus of a type in which the recording head is mounted on a carriage that reciprocally moves in a direction crossing the transport direction of paper, optically-curable ink is irradiated with light both when the recording head moves outward and when it moves homeward, and therefore one light emitting element row is arranged on each of right and left sides of nozzle rows of colors, as described in JP-A-2005-104108 and JP-A-2004-314304.
Unfortunately, if a fault occurs in one of the light emitting elements, such as LEDs, constituting the light emitting element rows during a recording operation, optically-curable ink discharged from as many as tens of nozzle openings for which the faulty light emitting element is responsible remain in a state in which all the optically-curable ink is yet to be cured. As a result, a useless printed matter with no commercial value is produced.
In JP-A-2005-104108 and JP-A-2004-314304 mentioned above, no description is given of measures to be taken in such a case where a fault occurs in a light emitting element. Recently, when consideration is given to the market of printed matter produced using optically-curable ink that is widely used, taking measures to counter the problem of a faulty light emitting element has become a challenge of urgent necessity.
That is, it is desirable that a fault be less likely to occur in a light emitting element constituting a light emitting element row, and that if a fault does occur in some of light emitting elements during a recording operation, optically-curable ink be cured to enable continuation of the recording operation.